1. Field of the Invention
Aspects of the present invention relate to an organic light emitting display, and more particularly, to an organic light emitting display that can avoid or reduce scratched wires and dark spot defects.
2. Description of the Related Art
An organic light emitting display is a self-emitting display that uses a phenomenon in which electrons and positive holes injected into an organic material through an anode and a cathode, respectively, are recombined to form excitons. The excitons thereby generate a light beam with a specific wavelength to release energy. The organic light emitting display does not require a separate light source, such as a backlight, resulting in low or lower power consumption. Furthermore, since a wide viewing angle and a fast response time of the organic light emitting display can be easily ensured, the organic light emitting display is expected to be a next generation display.
In terms of a driving method, the organic light emitting display is classified into a passive matrix type and an active matrix type. In recent years, the active matrix type organic light emitting display has become more prevalent over the passive matrix type organic light emitting display. The active matrix type organic light emitting display enables realization of low power consumption, high definition, fast response time, wide viewing angle, and light thin film characteristics.
In an active matrix type organic light emitting display, a pixel region is formed on a pixel substrate where an image is to be displayed. Furthermore, wires are provided around the pixel region along with a data driver and a scan driver to drive the pixel region in response to a signal input through pads of the wires. Pixels, each of which is a basic unit for image display, are arranged on the pixel region in a matrix form. An organic light emitting element is provided for each pixel such that a first pixel electrode of a positive polarity and a second pixel electrode of a negative polarity are sequentially formed with an emitting layer interposed therebetween. The emitting layer includes a red (R), green (G), and/or blue (B) organic material. In each of the pixels, a thin film transistor (TFT) is in contact with the organic light emitting element so that the pixels can be independently controlled.
In the organic light emitting display, the pixel substrate is encapsulated by an encapsulation substrate in order to protect the pixels. However, the wires and the pads are vulnerable to an externally imposed physical impact as the wires and the pads are not encapsulated to enable receipt of an external signal. In particular, as shown in FIGS. 6A, 6B, and 6C, if the wires are scratched, an electrical short may occur between the wires. As a result, driving of the pixel may be performed erroneously.
Moreover, if the second pixel electrode of the organic light emitting display is formed to be thin in the shape of a front electrode, a pin hole may be formed in the second pixel electrode as shown in FIG. 7, to result in dark spot defects. Accordingly, display quality of the organic light emitting display deteriorates.